1. Field of the Invention
This invention relates to the field of plumbing devices, and in particular to a toilet tank that provides a pressurized stream of water to facilitate the removal of materials in the bowl.
2. Description of Related Art
A flushing device for a toilet that uses a reduced amount of water is known from EP-A-0 352 712. Two water feeds to a toilet bowl are provided in this flushing device. One water feed leads to the edge of the bowl, and the other feed leads to a trap arranged in the lower area of the bowl. During flushing, the bowl is cleaned with one flow of flushing water, and the water present in the trap is set into motion with the other flow of flushing water. The minimum amount of water necessary for an effective flushing is substantially smaller in such a flushing device than in a flushing device with only one flushing flow for cleaning the toilet bowl. In the design shown in FIG. 1 of the referenced patent, the flushing device is designed as a so-called flushing valve. To control the two flows of flushing water, a relatively complicated control device is necessary here. In addition, it is disadvantageous in this design that disturbing noises are generated during flushing despite the relatively small amount of flushing water. In addition, flushing valves are not approved in certain countries. FIG. 7 of the referenced patent shows a design in which the water used for one flushing is stored in a flushing water tank. A branch pipe, which leads to the trap of the toilet bowl, is connected to a discharge pipe of the flushing water tank. A complicated control device is necessary in this design as well, and valves and pressure indicator means, with which the two flows of flushing water are controlled, are necessary in the pipes.
Similar flushing devices are shown in EP-A-0 369 377 and EP-A-0 415 432. Complicated control and regulating units are necessary in these designs as well.
It is an object of this invention to provide a flushing device of the class described above, which represents a substantially lower load for the water pipes than flushing valve-type devices. It is a further object of this invention to provide a flushing device that operates with less noise. It is a further object of this invention to achieve the necessary flushing effect with a minimal amount of flushing water.
These objects and others are achieved by providing a flushing device wherein a portion of the flushing water present in the flushing water tank is pressurized during the flushing process. This pressurized water is released to the outlet, which leads to the trap arranged in the lower area of the toilet bowl. It is therefore possible with the flushing device according to the present invention to accelerate the water in the trap such that this trap will be flushed better. The water of the trap is briefly set into motion, and more effective emptying of the trap is achieved. Only the toilet bowl must then be cleaned and the partially emptied trap must be refilled with the flushing flow which is subject to gravity. Thus, an amount of pressureless flushing water and an amount of pressurized flushing water are released during one flushing in the flushing device according to the present invention. Thus, a smaller amount of flushing water is needed at equal flushing effect than with a common flushing tank. Compared with flushing valve-type devices, the flushing device according to the present invention represents a substantially lower load for the water pipes, and it corresponds to a common flushing tank in this respect.
According to a variant of the present invention, the means with which an amount of flushing water can be pressurized has a piston-and-cylinder unit with a piston, to which water of the water supply pipe can be admitted during flushing. The piston is displaced by the pressure of the water from the supply pipe, and a defined amount of flushing water present in the unit is pressurized. Such a piston-and-cylinder unit may be accommodated in a flushing tank. Such a flushing tank can then be operated with a pushbutton.
Especially effective flushing is achieved if the water present in the piston-and-cylinder unit is released with a delay under pressure by means of a control device. It can be achieved as a result that the flushing flow which is subject to gravity and the pressurized flushing flow will act essentially simultaneously in the siphon or trap. This control device nay be designed simply as a float, which actuates a servo-controlled intake valve.
The present invention also pertains to a toilet unit wherein the nozzle is arranged inclined in relation to the horizontal such that the flushing water released through the nozzle exerts a movement directed downstream to the water present in the arch of the trap.